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Gabapentin in Blood, Plasma/Serum for GC or GC/MS Analysis
Using 100mg 1mL HyperSep C18
(Part Number: 60108-302)
Prepare Sample
To 500µL of 20% acetic acid add internal standard*
Mix/vortex
Add 500µL of blood, plasma/serum
Mix/vortex
Centrifuge as appropriate
Condition HyperSep C18 Extraction Column
1 x 3mL CH
3
OH
1 x 3mL DI H
2
O
1 x 1mL 100mM HCL
NOTE:
Aspirate at <3"Hg to prevent sorbent drying
Apply Sample
Load at 1 tomL/minute
Wash Column
1 x 3mL DI H
2
O
1 x 3mL ethyl acetate
1 x 3mL hexane
Dry column (5 minutes at >10"Hg) or until column is dry
Elution
1 x 1mL 2% NH
4
OH in CH
3
OH
Dry Eluate
Evaporate to dryness at <40°C
Derivatization
Add 50µL of ethyl acetate and 50µL of BSTFA (1%
TCMS)** and 50µL ethyl acetate
Cap and heat at 70°C for 30 minutes
Remove and allow to cool
Quantitate
Inject 1 to 2µL onto GC/MS
Compound
Primary
Secondary
Tertiary
Gabapentin-TMS
210
225
182
Gabapentin-D10-TMS*
220
235
192
*
Internal standard: 1-aminomethyl-1-cycloheptyl acetic acid (FID):Gabapentin-D10 (GC/MS)
** Part number TS-38831
Recommended GC Column
Part Number
TraceGOLD TG-5MS 30m x 0.25m x 0.25µm
26098-1420
Gabapentin in Blood, Plasma/Serum for LC/MS Analysis
Using 200mg 6mL HyperSep Verify-CX Extraction Column
(Part Number: 60108-722)
Prepare Sample
To 0.2 to 0.5mL of sample add 1mL of acetone
(dropwise) whilst vortexing
Add internal standard*
Mix/vortex and centrifuge as appropriate
Transfer organic phase to clean tube
Evaporate to dryness
Add 3mL of 100mM HCl
Mix/vortex and centrifuge as appropriate
Condition HyperSep Verify-CX Extraction Column
1 x 3mL CH
3
OH
1 x 3mL DI H
2
O
1 x 1mL 100mM HCl
NOTE:
Aspirate at <3"Hg to prevent sorbent drying out
Apply Sample
Load sample at 1 to 2mL/minute
Wash Column
1 x 3mL DI H
2
O
1 x 3mL ethyl acetate
1 x 3mL hexane
Dry column (10 minutes at >10"Hg)
Elute Gabapentin
1 x 3mL CH
3
OH containing 2% NH
4
OH
Collect eluate at 1 to 2mL/minute
Evaporation
Evaporate eluates under a gentle stream of nitrogen <40°
Dissolve residue in 100µL CH
3
OH
Inject 5µL of sample on to LC/MS
* Suggested internal standards: Gabapentin-D10, Aminocyclohexane-propionic acid
Recommended HPLC Column
Part Number
Hypersil GOLD 3µm, 150 x 2.1mm
25003-152130
Pharmaceutical/Biotech
Applications